19926366857 has 2 divisors, whose sum is σ = 19926366858. Its totient is φ = 19926366856.

The previous prime is 19926366853. The next prime is 19926366877. The reversal of 19926366857 is 75866362991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19796771401 + 129595456 = 140701^2 + 11384^2 .

It is a cyclic number.

It is not a de Polignac number, because 19926366857 - 2² = 19926366853 is a prime.

It is a super-2 number, since 2×19926366857² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19926366857.

It is not a weakly prime, because it can be changed into another prime (19926366851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9963183428 + 9963183429.

It is an arithmetic number, because the mean of its divisors is an integer number (9963183429).

Almost surely, 2^19926366857 is an apocalyptic number.

It is an amenable number.

19926366857 is a deficient number, since it is larger than the sum of its proper divisors (1).

19926366857 is an equidigital number, since it uses as much as digits as its factorization.

19926366857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29393280, while the sum is 62.

The spelling of 19926366857 in words is "nineteen billion, nine hundred twenty-six million, three hundred sixty-six thousand, eight hundred fifty-seven".